Event Statistics

Player challenge protocol for electronic line calling at the US Open includes three challenges per set plus one for tiebreakers.

In 2006, the US Open became the first Grand Slam to use electronic line calling technology, creating a "2 plus 1" player challenge system. The technology was introduced to improve officiating for players, while increasing the intrigue and excitement for in-stadium fans and television viewers. The new technology was immediately embraced by officials, players and fans.

In 2010, the "3 plus 1" player challenge system was introduced. All professional tennis events where an electronic line calling system is in place, including all Olympus US Open Series events this summer, use the "3 plus 1" protocol.

The on-court player challenge system for review of line calls at the US Open is as follows:

Each player is allowed a maximum of three incorrect challenges per set after which they are not permitted to challenge again in that set.

If a set goes to a tiebreaker, each player will receive one additional challenge.